Re: bin/54729: dmesg(8) trims leading whitespaces of kernel messages

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

The following reply was made to PR bin/54729; it has been noted by GNATS.

From: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: tsutsui%ceres.dti.ne.jp@localhost
Subject: Re: bin/54729: dmesg(8) trims leading whitespaces of kernel messages
Date: Tue, 31 Dec 2019 07:44:10 +0900

 >  It is probably possible to fix it to preserve the spaces (after
 >  the first one) after the timestamp
 
 The following diff restores format as pre-timestamp versions.
 
 Index: dmesg.c
 ===================================================================
 RCS file: /cvsroot/src/sbin/dmesg/dmesg.c,v
 retrieving revision 1.43
 diff -u -p -d -r1.43 dmesg.c
 --- dmesg.c	4 Jun 2019 11:59:05 -0000	1.43
 +++ dmesg.c	30 Dec 2019 22:32:56 -0000
 @@ -157,7 +157,7 @@ main(int argc, char *argv[])
  	long nsec, fsec;
  	int scale;
  	int deltas, quiet, humantime;
 -	bool frac;
 +	bool frac, postts;
  
  	static const int bmib[] = { CTL_KERN, KERN_BOOTTIME };
  	size = sizeof(boottime);
 @@ -262,6 +262,7 @@ main(int argc, char *argv[])
  	 */
  #ifndef SMALL
  	frac = false;
 +	postts = false;
  	scale = 0;
  #endif
  	for (tstamp = 0, newl = 1, log = i = 0, p = bufdata + cur.msg_bufx;
 @@ -310,6 +311,7 @@ main(int argc, char *argv[])
  				ADDC(ch);
  				ADDC('\0');
  				tstamp = 0;
 +				postts = true;
  				sec = fsec = 0;
  				switch (sscanf(tbuf, "[%jd.%ld]", &sec, &fsec)){
  				case EOF:
 @@ -375,8 +377,10 @@ main(int argc, char *argv[])
  				continue;
  #endif
  			case ' ':
 -				if (!tstamp)
 +				if (!tstamp && postts) {
 +					postts = false;
  					continue;
 +				}
  				/*FALLTHROUGH*/
  			default:
  #ifndef SMALL
 
 ---
 
 BTW, is it intentional that timestamp format is different between
 kernel (and /kern/msgbuf) and dmesg?
 
 https://nxr.netbsd.org/xref/src/sys/kern/subr_prf.c?r=1.181#506
 >     506 	n = snprintf(buf, sizeof(buf), "[% 4jd.%.*ld] ",
 
 >> [   1.0000000] NetBSD 9.0_RC1 (HPT5325) #0: Sun Dec  1 23:17:48 JST 2019
 
 
 https://nxr.netbsd.org/xref/src/sbin/dmesg/dmesg.c?r=1.43#358
 >     358 					printf(" %5jd%s", sec, radix);
 
 >> [     1.000000] NetBSD 9.0_RC1 (HPT5325) #0: Sun Dec  1 23:17:48 JST 2019
 
 ---
 Izumi Tsutsui